1. Field of the Invention
The present invention relates to a clutch connection control system for a motor-driven speed change apparatus in which gear shift and disconnection and connection of a clutch are performed by using an electric motor. In particular, the present invention relates to a clutch connection control system for variably controlling a connection speed of the clutch on the basis of turning speeds of a clutch drive side and a clutch driven side.
2. Description of Related Art
As opposed to a related speed change apparatus for carrying out gear shift by operating both a clutch pedal (or clutch lever) and a gear shift lever, a motor-driven speed change apparatus for electrically carrying out gear shift by using a motor has been known, for example, from Japanese Patent Laid-open No. Hei 1-122741.
To shorten a time required for clutch connection and improve riding comfort upon clutch connection, the above related art speed change apparatus is configured such that an operational speed of a clutch release mechanism, that is, a turning speed of a drive motor is controlled, as shown in FIG. 33 of the present invention, such that a turning speed difference between a clutch drive side and a clutch driven side follows a predetermined time function.
An earlier application (Japanese Patent Laid-open No. Hei 11-82709) filed by the present applicant has disclosed a technique in which a clutch release mechanism upon clutch connection is operated at a high speed until a predetermined timing estimated as a clutch connection point and is operated at a low speed after the predetermined timing.
With this configuration, since the clutch is moved at a high speed in an operational region in which a clutch drive side is not in contact with a clutch driven side and is moved at a low speed in an operational region in which the clutch drive side is connected to the clutch driven side, it is possible to shorten the time required for speed change and to improve riding comfort upon speed change.
According to the above-described first related art (Japanese Patent Laid-open No. Hei 1-122741), when the turning speed difference between the clutch drive side and clutch driven side becomes zero, it is decided that the semi-clutch state is ended, that is, the clutch connection operation is ended. However, even when the turning speed difference between the clutch drive side and clutch driven side becomes zero, the operation of the drive system for driving the clutch is not ended yet. More specifically, the operation for returning respective portions of the drive system to initial positions is continued.
According to the above-described first related art, however, it has not been examined at all to shorten a time required for ending automatic speed change by returning respective portions of the drive system to initial positions after the turning speed difference between the clutch drive side and clutch driven side becomes zero.
According to the above-described second related art (Japanese Patent Laid-open No. Hei 11-82709), the connection operation is carried out at a high speed until a clutch connection start point (semi-clutch state start point); however, after the start of clutch connection (start of the semi-clutch state), even if the semi-clutch state is converged and thus the clutch connection is ended, the connection operation at a low speed is continued until respective portions of the clutch drive system are returned to initial positions. Accordingly, a delicate difference between the end timing of the clutch connection decided by the driver""s bodily sensation and the end timing of clutch connection mechanically decided by an automatic speed change apparatus occurs.
As a result, when the driver immediately performs, after termination of the initial speed change operation, the next speed change operation, there may occur an inconvenience in that since the automatic speed change apparatus cannot accurately respond to the driver""s command for speed change, the driver feels a sense of incongruity.
An object of the present invention is to solve the above-described technical problems of the related art and to provide a clutch connection control system capable of shortening a time required for automatic speed change, preventing the degradation of riding comfort upon clutch connection, and ensuring good operability.
To achieve the above object, according to the present invention, there is provided a clutch connection control system comprising: clutch release means for disconnecting and connecting a clutch drive side from and to a clutch driven side by turning an electric motor; drive side turning speed detecting means for detecting a turning speed of said clutch drive side; driven side turning speed detecting means for detecting a turning speed of said clutch driven side; turning speed difference detecting means for detecting a difference between said detected turning speed of said clutch drive side and said detected turning speed of said clutch driven side; and control means for controlling a disconnecting and connecting said clutch, which is disconnected and connected by said clutch release means, on the basis of said detected turning speed difference; wherein said control system further includes comparing means for comparing said turning speed difference with a specific value; and said control means carries out clutch connection at a first speed until said turning speed difference becomes a specific value or less, and said control means carries out clutch connection at a second speed higher than said first speed after said turning speed difference becomes said specific value or less.
With this configuration, since the connection operation is performed at a low speed in a period exerting an effect on a riding comfort, which period ranges from the clutch connection start point (semi-clutch state start point) to the clutch connection end point (semi-clutch state end point), it is possible to ensure good riding comfort. Furthermore, the connection operation is performed at a high speed in a period exerting no effect on a riding comfort, which period ranges from the clutch connection end point to the end of automatic speed change. Accordingly, it is possible to shorten a time required for automatic speed change, to prevent the degradation of riding comfort upon clutch connection, and to ensure good operability.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.